pH-dependent perforation of macrophage phagosomes by listeriolysin O from Listeria monocytogenes.
pH-dependent perforation of macrophage phagosomes by listeriolysin O from Listeria monocytogenes.
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DOI：
10.1084/jem.186.7.1159
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发表时间：
1997-10-06
期刊：
影响因子：
--
通讯作者：
Swanson JA
中科院分区：
文献类型：
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作者：
Beauregard KE;Lee KD;Collier RJ;Swanson JA
成孔毒素李斯特菌溶血素 O (LLO) 是单核细胞增生李斯特菌从吞噬泡中逃逸的主要毒力因子。在这里，我们描述了 LLO 液泡穿孔的 pH 依赖性，使用膜非渗透性荧光团 8-羟基芘-1,3,6-三磺酸 (HPTS) 来监测小鼠骨髓源性巨噬细胞中液泡的 pH 值和完整性。当含有野生型单核细胞增生李斯特菌的酸性液泡显示出 pH 值突然升高以及 HPTS 释放到胞质溶胶中时，观察到穿孔。这些变化在 LLO 缺陷突变体中没有观察到。穿孔发生在酸性液泡 pH 值 (4.9–6.7) 下，当巨噬细胞用溶酶体氯化铵或巴弗洛霉素 A1 处理时，穿孔发生率降低或完全预防。我们得出结论，酸性 pH 值有利于 LLO 体内活性。
The pore-forming toxin listeriolysin O (LLO) is a major virulence factor implicated in escape of Listeria monocytogenes from phagocytic vacuoles. Here we describe the pH-dependence of vacuolar perforation by LLO, using the membrane-impermeant fluorophore 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) to monitor the pH and integrity of vacuoles in mouse bone marrow–derived macrophages. Perforation was observed when acidic vacuoles containing wild-type L. monocytogenes displayed sudden increases in pH and release of HPTS into the cytosol. These changes were not seen with LLO-deficient mutants. Perforation occurred at acidic vacuolar pH (4.9–6.7) and was reduced in frequency or prevented completely when macrophages were treated with the lysosomotropic agents ammonium chloride or bafilomycin A1. We conclude that acidic pH facilitates LLO activity in vivo.